Manual of Practice for an Effective Anti-icing Program: A Guide

0,89

MB

For Highway Winter Maintenance Personnel

69

stron

5019

ID

Cold Regions Research and Engineering Laboratory

2005

rok

TABLE OF CONTENTS

1. INTRODUCTION 1

1.1 PURPOSE OF THE MANUAL. 1

1.2 SCOPE AND ORGANIZATION OF THE MANUAL 2

2. ANTI-ICING IN THE CONTEXT OF A WINTER MAINTENANCE PROGRAM 3

2.1 LEVEL OF SERVICE 3

2.2 CLIMATIC CONDITIONS. 3

2.3 DEICING AND ANTI-ICING . 5

2.4 ANTI-ICING AS A SYSTEMATIC PRACTICE 5

2.5 ABRASIVES USE 6

3. ANTI-ICING PROGRAM TOOLBOXES . 7

3.1 OPERATIONS TOOLBOX. 7

3.1.1 Solid chemical application capability. 7

3.1.1.1 Solid materials and gradation 8

3.1.1.2 Equipment 8

Solid material spreaders. 8

Solid chemical storage facilities 10

3.1.2 Liquid chemical (chemical solution) application capability. 11

3.1.2.1 Chemical solutions. 11

3.1.2.2 Equipment 11

Liquid application equipment 11

Chemical solution production facilities; salt brine. 17

Chemical solution production facilities; liquid CMA. 17

Chemical solution storage facilities. 20

3.1.3 Prewetted solid chemical application capability . 20

3.1.3.1 Materials 21

Solid materials and gradation 21

Prewetting solutions. 22

3.1.3.2 Prewetting techniques and equipment. 22

Prewetting of stockpile . 22

Prewetting of a load or while loading 23

Prewetting by spreader spray systems 23

Chemical solution production and chemical storage facilities. 25

3.1.4 Plowing capability 25

3.1.4.1 Types of snowplows 25

3.1.4.2 Cutting edges 25

3.1.4.3 Slush blades 26

3.2 DECISION-MAKING TOOLBOX . 26

3.2.1 Weather forecast information. 26

3.2.2 Road and road weather information 26

3.2.2.1 Road information . 26

3.2.2.2 Road Weather Information Systems (RWIS) and their components . 27

3.2.2.3 Role of thermal mapping . 27

3.2.3 Nowcasting. 28

3.2.4 Traffic information 28

3.2.5 Patrols 29

3.2.6 Evaluations of treatment effectiveness . 29

3.3 PERSONNEL TOOLBOX. 30

3.3.1 Trained personnel for anti-icing decision making and operations 30

3.3.2 Deployment of personnel . 30

4. RECOMMENDED ANTI-ICING PRACTICES . 33

4.1 INITIAL OPERATION 33

4.1.1 Information assembly 33

4.1.2 Decision point . 34

4.1.3 Action . 34

4.1.3.1 Apply chemical . 34

Recommendations for use of liquid chemicals 34

Recommendations for use of solid and prewetted solid chemicals. 35

4.1.3.2 Plow . 35

4.1.3.3 Do nothing. 35

4.2 SUBSEQUENT OPERATIONS 36

4.2.1 Monitoring of conditions . 36

4.2.2 Action . 36

4.2.2.1 Apply chemical . 36

4.2.2.2 Plow . 37

4.2.2.3 Do nothing. 37

4.3 SPECIAL CONSIDERATIONS 37

4.3.1 Traffic condition 37

4.3.2 Wind. 38

4.3.3 Hybrid precipitation events. 38

4.3.4 Prewetting quantities . 38

4.3.5 Development of snowpack and bond 38

4.3.6 Use of abrasives 38

4.4 POST-STORM ASSESSMENT OF OPERATIONS. 39

APPENDIX A. SELECTED CHEMICALS AND THEIR PROPERTIES 40

A.1 CALCIUM CHLORIDE, CaCl2 40

A.1.1 Introduction. 40

A.1.2 Preparation of liquid CaCl2. 40

A.1.2.1 Method 1 (Known mixing container volume) 40

A.1.2.2 Method 2 (Unknown mixing container volume) . 41

A.1.2.3. Additional comments. 41

A.2 SODIUM CHLORIDE, NaCl. 42

A.2.1 Solid NaCl . 42

A.2.2 Preparation of liquid NaCl 43

A.2.2.1 Method 1 (Known mixing container volume) 44

A.2.2.2 Method 2 (Unknown mixing container volume) . 44

A.2.2.3 Additional comments 45

A.3 MAGNESIUM CHLORIDE, MgCl2 . 45

A.4 CALCIUM MAGNESIUM ACETATE, [CaMg2 (CH3COO)2]6 45

A.4.1 Introduction. 45

A.4.2 Preparation of liquid CMA . 45

A.5 POTASSIUM ACETATE, KC2H3O2. 45

APPENDIX B. FREEZING-POINT OF CHEMICAL SOLUTIONS. 48

B.1 INTRODUCTION 48

B.2 NaCl AND CaCl2 . 49

B.3 MgCl2 . 50

B.4 CMA AND KAc 51

APPENDIX C. OPERATIONS GUIDE FOR MAINTENANCE FIELD PERSONNEL . 54

C.1 INTRODUCTION 54

C.2 GUIDANCE FOR ANTI-ICING OPERATIONS 54

C.3 GLOSSARY OF TERMS. 55

REFERENCES. 63